Page 50 - 15Diarrhoeaandvomiting

Diagnosis

Table 3.2 Duration of diarrhoea in 595 children with gastroenteritis a 44

Clinical study group Number Mean duration (days)
Rotavirus 203 (34%) 4.8
Salmonellae 98 (16%) 12.3
Escherichia coli 55 (9%) 6.8
Campylobacter 36 (6%) 7.4
Shigellae 22 (4%) 7.9
Rotavirus and salmonellae 44 (7%) 12.9
Rotavirus and others 26 (4%) 7.4
No pathogen 111 (19%) 5.6
Total 595 (100%) 7.4
a Five children with Aeromonas hydrophila were excluded from the analysis.

admitted to hospital. Cases were children with diarrhoea persisting for more than 14 days while
the controls had all recovered within 7 days of admission. For each case, two age-matched
controls were recruited. If the controls became cases either during hospital stay or follow-up,
they were withdrawn and fresh controls recruited. The episode of diarrhoea was considered to
be controlled when a child had no diarrhoea for 2 consecutive days. Fifteen potential risk factors
were examined. After adjusting for co-variables by multiple logistic regression analysis, the factors
independently associated with persistent diarrhoea were malnutrition (adjusted OR 2.9; 95% CI
1.9 to 4.5), stool with blood and/or mucus (adjusted OR 2.4; 95% CI 1.3 to 4.3), indiscriminate
use of antibiotics (adjusted OR 2.4; 95% CI 1.6 to 3.9), stool frequency more than 10 per day
(adjusted OR 1.8; 95% CI 1.2 to 2.8) and persistence of dehydration for more than 24 hours
(adjusted OR 1.4; 95% CI 1.2 to 1.7). [EL = 2+]

Evidence summary

Results from three cross-sectional studies [EL = 3] suggested that viral gastroenteritis was associated
with a shorter duration of diarrhoea than bacterial gastroenteritis. The fourth cross-sectional study
from Italy did not report the duration separately for the viral and bacterial infections. There was
consistent evidence from these studies to indicate that vomiting and dehydration were more
common with viral gastroenteritis while bloody diarrhoea and abdominal pain were more often
associated with bacterial gastroenteritis. A case–control study [EL = 2+] reported that malnutrition,
bloody and/or mucoid stools, indiscriminate use of antibiotics, high stool frequency (>10 per
day), and persistence of dehydration (>24 hours) were factors independently associated with an
increased risk of persistent diarrhoea.

GDG translation from evidence to recommendation
Several cross-sectional studies have provided consistent evidence of differences in the
manifestations of viral and bacterial gastroenteritis. Viral gastroenteritis is of shorter duration
than bacterial gastroenteritis and associated with an increased risk of vomiting and dehydration.
Bacterial gastroenteritis is more often associated with severe abdominal pain and sometimes with
bloody diarrhoea.

While the GDG recognised that the study of risk factors for persistent diarrhoea was based on a
population in India, the findings were nevertheless important, especially given the multi-ethnic
composition of the UK population and the increasing frequency of overseas travel. Some potentially
important risk factors for persistent diarrhoea were identified: persistence of dehydration for more
than 24 hours after appropriate fluid therapy, presence of blood and/or mucus in the stool, stool
frequency greater or equal to 10 per day, indiscriminate use of antimicrobials, weight loss and
poor nutritional status.

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